Strand guide, in particular for a continuous steel slab casting installation

ABSTRACT

The present invention relates to a strand guide ( 1 ), in particular for a steel slab continuous casting installation, comprising a number of segments ( 2 ) that support a strand on two opposite sides ( 4, 5 ) thereof with support elements ( 6, 7 ), wherein the support elements ( 6, 7 ) are arranged in at least one lower frame ( 8 ) and at least one upper frame ( 9 ) for guiding the strand ( 3 ) in a conveying direction, and wherein the frames ( 8, 9 ) are arranged on at least one central bar ( 10 ). In order to facilitate exchange of segments or their parts, according to the intention there is available means ( 11 ) with which the at least one upper and/or at least one lower frame ( 8, 9 ) can be adjusted relative to the at least one central bar ( 10 ) in a conveying direction (F) or in opposite direction.

The invention relates to a strand guide, in particular, for a steel slab continuous casting installation and including a number of segments that support a strand on its two opposite sides with support elements, wherein the support elements are arranged in at least one lower frame and at least one upper frame for guiding the strand in a conveying direction, and wherein the frames are arranged on at least one central bar.

A strand guide of this type is disclosed, e.g., in DE 198 24 366 A1. The strand guide has a number of segments which form a casting bow and which have opposite rows of guide and drive rollers. The rollers are supported in an upper frame and a lower frame. The frames are arranged on a central bar (or side frames).

Similar solutions are disclosed in DE 1 965 115 A1 DE 40 34 141 C1, EP 0 879 106 B1, EP 1 286 796 B1 and DE 26 20 888 C2.

With the known solutions, mounting and dismounting a circular segment together with the central tie bar in or from strand guide present a problem. The dismounting or mounting of a segment and an associated therewith, displacement of the segment in direction of the center of the casting bow (i.e., transverse to the segment axis or to the conveying direction) can cause collision problems with adjacent segments.

This is particularly the case with casting machine with a small casting radius. Here, often, the segments can be withdrawn only by forming the segment frame so that it corresponds to the dismounting format. This dismounting format mostly is smaller than the largest of the to-be-cast format. As a result of operational disturbances during casting of the largest format, increased difficulties can arise during dismounting of a segment.

Accordingly, an object of the invention is to so modify the stand guide of the above-described type that even at very small casting radii, dismounting and mounting of a segment or a portion of the same is possible in an improved manner.

The solution for this object according to the invention is characterized in that there is available means with which the at least one upper and/or at least one lower frame can be adjusted relative to the at least one central bar in a conveying direction or in opposite direction.

At that, at most, one central bar is provided on each side of the segment.

The means comprises at least one actuator that can displace one of the frames in the conveying direction relative to the central bar. The actuator can be formed as a double-action piston-cylinder unit. It can also include two piston-cylinder units arranged on the central tie bar.

The actuator can also be formed as a hydraulic piston-cylinder system, a pneumatic piston-cylinder system, or a mechanical longitudinally adjusting element. In the latest case, the actuator can have an electric motor-driven, threaded spindle system.

Advantageously, the support elements are formed as driven and non-driven rollers supported rotatably in the frames. The segments advantageously form a casting bow. They also can be used in vertical or horizontal region of the guide strand.

Under a central bar is generally understood a segment lower frame construction formed for guiding the upper frame. Also, several side frame bars can be formed on one side per segment.

With the solution according to the invention, it is achieved that, in particular, in casting machines with small casting radii, dismounting or mounting of a segment is substantially simplified or, under certain operational conditions, becomes at all possible for the first time. For dismounting a segment, the upper frames of the adjacent segments are so displaced by the mentioned adjusting means, that withdrawal of a segment is possible without a problem, i.e., collision-free. After displacement of the upper frames of the adjacent segments, a continuous casting segment can be withdrawn along its segment axis, i.e., transverse to the fixed side without collision with the adjacent segments.

An embodiment of the invention is shown in the drawings. The drawings show:

FIG. 1 a schematic side view of a casting bow of a strand guide of a continuous casting machine;

FIG. 2 three adjacent segments of the casting bow in a possible operational position; and

FIG. 3 the three segments according to FIG. 2 in a dismountable position of one of the segments.

FIG. 1 shows a casting bow of a strand guide of a continuous casting machine. In a known manner, the casting bow consists of a number of segments 2 which are so positioned relative to each other that an arc-shaped path is provided for a cast strand (not shown here) for deflecting it, beneath the mold, from a vertical to a horizontal. Each segment 2 has, as essential components, two frames 8 and 9, namely, a lower frame 8 and an upper frame 9 in which support elements 6, 7 in form of rollers are mounted. Rollers 6, 7 can be driven or non-driven, with one of the frames 8, 9 capable of having rollers of both types. Thereby, a path for the cast strand in conveying direction F is defined.

The construction of segment 2 according to the embodiment of the invention is shown in FIG. 2. The segments forming the casting bow are designated with 2′, 2″, 2′″, and 2″″ (in FIG. 3). The segments 2 intended for use are segments with a central tie bar. Each segment 2′, 2,″ 2′″ has a central bar 10 on T-shaped base portion of which a lower frame 8 (not shown in FIGS. 2 and 3) is fixedly secured and which carries support elements in form of rollers 6 which support a side 4 of the strand 3. On the central bar 10, an upper frame 9 is arranged and which carries uniform support elements in form of rollers 7 which guide the side 5 of the strand 3.

The adjustment of rollers 6 and 7 relative to each other, i.e., the adjustment of the gap between the rollers 6 and 7 for the strand 3 is carried out with an adjusting cylinder 17 as such is known.

It is essential that the upper frame 9 is not fixedly mounted on the central bar 10, taking in consideration a contemplated, in each case, adjustment of the roller gap between rollers 5, 6 with the adjusting cylinder 17, but rather is so arranged on the central bar 10 with means 11 that displacement of the upper frame 9 relative to the central bar 10 in the conveying direction is possible. The means 11 has an actuator 12 that is available with two piston-cylinder units with which the upper frame can be displaced relative to the central bar 10 in the conveying direction F or in the opposite direction. To this end, a suitable slideway is provided that insures a stable displacement movement of the upper frame 9 relative to the central bar 10 with actuator 12.

The thereby achievable effect follows from the synopsis of FIGS. 2 and 3. If a segment 2, in the example of FIG. 2 or 3, the right segment 2′″, is dismounted, a certain mounting space is necessary therefore in order to be able to lift the segment in direction of the center of the casting bow.

FIG. 2 shows a possible operational position of segments 2. Further, here, a withdrawal space boundary 13 is shown with a dot-dash line. If the right segment 2′″ is displaced in direction of the casting bow center, it would collide with the upper frame 9 of the middle segment 2″ at a point marked with numeral 14.

To prevent this, it is proceeded as shown in FIG. 3.

The upper frame 9 of the middle segment 2″ (as well as the frame of only roughly shown in FIG. 3, rightward segment 2″″) is displaced relative to the central bar 10 by the actuator 12 in direction opposite the conveying direction F. As a result, the central axis 15 of the upper frame 9 moves away from the central axis 18 of the central bar 10. As can be seen in FIG. 3, the upper frame 9 is displaced from the central bar 10 by the actuator 12 by a displacement path X. Thereby, a mounting clearance 16 is formed in the region of the withdrawal space boundary 13. The same takes place with the upper frame of the segment 2″″ that adjoins the segment 2′″ on the right, which is displaced in the conveying direction F, so that a corresponding mounting clearance is available in the region of the other withdrawal space boundary 19.

The segment 2′″, shown in FIG. 3, can be lifted in the direction of the center of the casting bow out off the strand guide collision-free.

For adjustment of the actuator 12, conventional systems can be used. According to one of the embodiment, use of a hydraulic piston-cylinder system is contemplated. However, it is also possible to incorporate an electrical system, i.e., for example, a threaded spindle or any other mechanical drive and an electric motor for driving the same.

Thus, the invention contemplates displacement of the upper frames of the segments with suitable adjusting elements transverse to a segment axis (parallel to the fixed side) to provide a mounting space for mounting or dismounting a segment.

The embodiment of the actuator 12, which is used in the exemplary embodiment, permits a selective displacement of the upper frame 9 in the Figures leftwardly and rightwardly with two actuation cylinders, after which, a segment is mounted or dismounted.

FIG. 2 illustrates a possible operational position of the device. It should be noted that a possible variable adjustment of the upper frame 9 can also be used during casting operation, e.g., to be able to carry out displacement of straightening point.

The present invention is advantageously applicable to arched segments of slabs and thin slab continuous casting installations.

REFERENCE NUMERALS

-   1 Strand guide -   2 Segment -   2′, 2″ Segments -   2′″ Segment -   2″″ Segment -   3 Strand -   4 Strand side -   5 Strand side -   6 Support element (roller) -   7 Support element (roller) -   8 Lower frame -   9 Upper frame -   10 Central bar -   11 Adjusting means -   12 Actuator -   13 Dismounting space boundary -   14 Collision -   15 Central axis of the upper frame -   16 Mounting clearance -   17 Adjusting cylinder -   18 Central axis of the central bar -   19 Dismounting space boundary -   F Conveying direction -   X Displacement path 

1. A strand guide (1), in particular for a steel slab continuous casting installation, comprising a number of segments (2) that support a strand on two opposite sides (4, 5) thereof with support elements (6, 7), wherein the support elements (6, 7) are arranged in at least one lower frame (8) and at least one upper frame (9) for guiding the strand (3) in a conveying direction, and wherein the frames (8, 9) are arranged on at least one central bar (10), characterized in that there is available means (11) with which the at least one upper and/or at least one lower frame (8, 9) can be adjusted relative to the at least one central bar (10) in a conveying direction (F) or in opposite direction.
 2. A strand guide according to claim 1, characterized in that a central bar (10) is provided as each side of a segment (2).
 3. A strand guide according to claim 1, characterized in that the segments (2) form a casting bow.
 4. A strand guide according to claim 1, characterized in that the means (11) comprises at least one actuator (12) that can displace one of the frames (8) in the conveying direction (F) relative to the central bar (10).
 5. A strand guide according to claim 4, characterized in that the actuator (12) is formed as a double-action piston-cylinder unit.
 6. A strand guide according to claim 4, characterized in that the actuator (12) comprises two piston-cylinder units arranged on the central bar (10).
 7. A strand guide according to claim 4, characterized in that the actuator (12) is formed as a hydraulic piston-cylinder system.
 8. A strand guide according to claim 4, characterized in that the actuator (12) is formed as a pneumatic piston-cylinder system.
 9. A strand guide according to claim 4, characterized in that the actuator (12) is formed as a mechanical longitudinally adjusting element.
 10. A strand guide according to claim 9, characterized in that the actuator (12) comprises an electric motor-driven threaded spindle system.
 11. A strand guide according to claim 1, characterized in that the support elements (6, 7) are formed as driven or non-driven rollers rotatably supported in the frames (8, 9). 